Drug interactions
Cabotegravir + Efavirenz
Severity: Major
Cabotegravir and Efavirenz: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Efavirenz induces UGT1A1, the main enzyme clearing cabotegravir, and substantially lowers its concentrations. This could cause loss of virologic suppression and resistance. Oral and long-acting cabotegravir are intended only with rilpivirine as a complete regimen.
What this interaction means in plain words
Cabotegravir and Efavirenz can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Cabotegravir belongs to Anti Virals; Efavirenz belongs to Anti Virals.
Why it happens
Efavirenz induces UGT1A1 and CYP3A4, increasing cabotegravir clearance.
What to do
Do not combine; use an alternative regimen not relying on cabotegravir with efavirenz. For PrEP or treatment, choose agents without strong inducers.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Other interactions of Cabotegravir
- Apalutamide + Cabotegravir Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Cabotegravir + Oxcarbazepine Contraindicated
- Cabotegravir + Phenobarbitone Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Cabotegravir + Rifabutin Contraindicated
Frequently asked questions
Can I take Cabotegravir with Efavirenz?
MediHelp rates the interaction as major. Cabotegravir and Efavirenz can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Efavirenz induces UGT1A1, the main enzyme clearing cabotegravir, and substantially lowers its concentrations. This could cause loss of virologic suppression and resistance. Oral and long-acting cabotegravir are intended only with rilpivirine as a complete regimen.
How serious is the interaction between Cabotegravir and Efavirenz?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not combine; use an alternative regimen not relying on cabotegravir with efavirenz. For PrEP or treatment, choose agents without strong inducers.
What other medicines interact with Efavirenz?
MediHelp also lists interactions of Efavirenz with, for example, Cobimetinib, Dienogest / estradiol valerate, Dihydroergotamine intranasal. The full list is on the Efavirenz page.
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